This invention relates in general to an apparatus for cooling harvested fruits and vegetables prior to transportation from the harvesting site. More particularly, the invention relates to such an apparatus which cools the harvested produce inside the transport means. Even more particularly, the invention relates to an apparatus which is self-contained, portable, and utilizes forced air circulation and water-to-air heat exchange to cool the produce.
Once fruits and vegetables are harvested, the ripening or spoilage process begins immediately. It is well known that cooling or refrigeration of the produce slows ripening and reduces this deterioration, thus increasing shelf life and freshness. The more rapidly the produce is cooled following harvest, the better the results. Since harvesting usually occurs during warm weather months, the produce contains a large amount of field heat. Additionally, the transport trailers into which the produce is loaded will have a high residual heat. Finally, the produce itself creates heat through respiration. The deterioration due to heat is directly related to loss of moisture from the produce, which shortens shelf life and reduces the quality of the produce. The differential in vapor pressure between the produce cells and the surrounding air determines the rate of moisture loss. Low air temperature and high moisture content lowers moisture loss from the produce. It is important to lower the surface temperature of the produce, remove the heat from the air in the transport trailer and maximize the moisture content of the air in the trailer as quickly as possible.
Devices to perform cooling of this general nature have long been known. In U.S. Pat. No. 2,293,316, Stebbins shows an air circulating device for cooling produce in trailers, trucks or train cars using a large fan and cooling coils, as does Wilson et al. in U.S. Pat. No. 2,778,206. More recently, devices have been developed which perform: the task in an improved manner, such as shown by Windecker in U.S. Pat. No. 4,598,555, McDonald et al. in U.S. Pat. No. 4,934,255 and Davis et al. in U.S. Pat. No. 5,054,291.
It is an object of the invention to improve upon the known prior art by providing an apparatus which maximizes the cooling efficiency of the process by decreasing cooling time and maintaining high moisture content, allows multiple transport trailers to be cooled at the same time, and maximizes the energy efficiency of the cooling means itself. In furtherance of this object, an apparatus is provided which comprises multiple ports for connection with individual transport trailers, the ports having individual forced air means, air ingress means and air egress means, the air egress means for all ports connecting to a common cool air chamber and the air ingress means for all ports connecting to a common warm air chamber, the two chambers separated by a single air to water heat exchanger.